Unit 1 Test Flashcards
Which is not a reason why measurements are important?
They give us an absolute analysis of the world around us.
Which is not an mks unit?
centimeter
How are seconds defined?
They are based on the time it take cesium atoms to vibrate.
How is a kilogram defined?
by a platinum brick in Europe
Which is the definition of a derived unit?
A unit which is based on other (basic) units.
How many significant figures are in the quantity
9.86 m/s ^2?
3
What is the difference between a vector and a scalar?
A vector has both magnitude and direction; scalars have only magnitude
Which of the following is not an example of a vector?
mass
If the x-component of a vector is 3 and the y-component is 4, what is the magnitude of the vector?
5
If V A + V B = V C which of the following is not true?
|A| + |B| = |C|
If vector A makes an angle of 37 degrees with the x-axis and has a length Ax=12, what is the length of Ay?
9
Which of the following is the sign of the scalar product of two vectors that have an angle of 79° between them?
positive
What do you obtain if you calculate the following product of 3 vectors: A(B*C)? (Assume that vectors B and C are not at right angles to one another.)
a vector
What is the scalar product of two perpendicular vectors?
What is the scalar product of two perpendicular vectors?
Which is not true?
Vector products and scalar products both change sign for angles greater than 90°.
Which of the following results from (AB)C, where A, B, and C are all vectors?
(Assume that none of the cross products results in zero.)
a vector
Torque is given by the formula, t = F*d, where F is a force and d is a displacement. Which of the following is the magnitude of torque resulting from a 2.4 N force applied 17cm from the point of rotation, if the force is applied perpendicular to the displacement vector?
0.41 N⋅m
If the cross product of a vector of length 5 and a vector of length 3 results in a vector of length 10, what is the angle between them?
42°
If a vector pointing toward the north is crossed with one pointing toward the east, the resulting vector is pointing ____________.
down
If a vector of magnitude 12 pointing in the x-direction is vector multiplied by a vector of magnitude 6 pointing in the y-direction, what is the magnitude of the resulting vector?
72
